diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index d69a0ff4ab9f..9b3281726352 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -545,6 +545,8 @@ protected:
     Builder.defineMacro("__ELF__");
     if (Opts.POSIXThreads)
       Builder.defineMacro("_REENTRANT");
+    if (this->HasFloat128)
+      Builder.defineMacro("__FLOAT128__");
   }
 public:
   OpenBSDTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
@@ -552,11 +554,11 @@ public:
     this->TLSSupported = false;
 
       switch (Triple.getArch()) {
-        default:
         case llvm::Triple::x86:
         case llvm::Triple::x86_64:
-        case llvm::Triple::arm:
-        case llvm::Triple::sparc:
+          this->HasFloat128 = true;
+          // FALLTHROUGH
+        default:
           this->MCountName = "__mcount";
           break;
         case llvm::Triple::mips64:
diff --git a/clang/test/CodeGenCXX/float128-declarations.cpp b/clang/test/CodeGenCXX/float128-declarations.cpp
index e1604a61cac7..f1db8f41c608 100644
--- a/clang/test/CodeGenCXX/float128-declarations.cpp
+++ b/clang/test/CodeGenCXX/float128-declarations.cpp
@@ -8,6 +8,10 @@
 // RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86
 // RUN: %clang_cc1 -emit-llvm -triple systemz-unknown-linux-gnu -std=c++11 \
 // RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-SYSZ
+// RUN: %clang_cc1 -emit-llvm -triple i686-pc-openbsd -std=c++11 \
+// RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86
+// RUN: %clang_cc1 -emit-llvm -triple amd64-pc-openbsd -std=c++11 \
+// RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86
 //
 /*  Various contexts where type __float128 can appear. The different check
     prefixes are due to different mangling on X86 and different calling